Szilárd, On Friday 08 May 2015 21:18:12 Szilárd Páll wrote: > >> What is your goal with using CPUSETs? Node sharing? > > > > Correct. While it might be possible to see the cores that have been > > assigned to the job and do the correct 'pin setting' it would probably be > > ugly. > > Not sure what you mean by "see the cores".
Sorry, I tend to anthropomorphize computers when I try to understand them ;-) If I request X cores from the queueing system, it will create a CPUSET of X cores. If I call omp_get_num_procs(), it will report X even if there are more physical cores on the system. This way OpenMP plays nice with the queuing system. > Also not sure why is it > more ugly to construct a CPUSET than a pin offset, but hey, if you > want both performance and node sharing with automated resource > allocation, the solution won't be simple, I think. The queuing system does the work of creating the CPUSET for me. One thing I was worried about is that I'm not guaranteed a contiguous set of processors in the CPUSET. If I ask for 4 cores, I may be assigned 1, 3, 5 and 6 for example. In the end, I think I can live without the performance increase of pin'ing the threads. Since the threads will be confined to the CPUSET, I'm guessing the threads are less likely to migrate. Cheers, Malcolm -- Malcolm Tobias 314.362.1594 -- Gromacs Users mailing list * Please search the archive at http://www.gromacs.org/Support/Mailing_Lists/GMX-Users_List before posting! * Can't post? Read http://www.gromacs.org/Support/Mailing_Lists * For (un)subscribe requests visit https://maillist.sys.kth.se/mailman/listinfo/gromacs.org_gmx-users or send a mail to gmx-users-requ...@gromacs.org.
